321 samocha 9 00- final_go 100 m3
TRANSCRIPT
High density production of the Pacific White Shrimp, Litopenaeus vannamei, in zero-
exchange, biofloc-dominated grow-out system: the challenge of Vibrio
Tzachi Samocha1, Leandro Castro1, David Prangnell1, Tom Zeigler2, Craig Browdy2, Tim Markey2, Darrin Honious3, and Bob Advent4
1Texas A&M AgriLife Research Mariculture Lab at Flour Bluff, Corpus Christi, Texas2Zeigler Bros., Gardners, Pennsylvania
3YSI, Yellow Springs, Ohio4a3 All Aqua Aeration, Orlando, Florida
Aquaculture America 2015 February 19-22, 2014 New Orleans, Louisiana
Introduction Numerous studies documented excellent
performance of Litopenaeus vannamei in no exchange, high-density, biofloc-dominated systems
However, recent findings suggest that shrimp in these systems can be affected by bacterial disease outbreaks
In most cases, these outbreaks caused by pathogenic Vibrio species
Better monitoring, prevention & control methods of pathogenic Vibrio are needed to improve the economic viability of these systems
Objectives Document the impact of Vibrio outbreaks on
shrimp after exposure to multiple stressors Study the performance of L. vannamei juveniles
and the changes in selected WQ indicators in high-density, biofloc-dominated, no water exchange RWs operated with a3 injectors
Determine if the a3 injectors can maintain adequate water mixing and DO levels in RWs stocked with juveniles of L. vannamei at high-density in biofloc-dominated water operated with no exchange
Materials & MethodsA 38-d GO study in two 100 m3 greenhouse-
enclosed RWs, stocked with juveniles (6.45 g) at 458 shrimp/m3
RWs filled with biofloc-rich water (87.5%) from an earlier 62-d nursery trial + NSW (12.5%)
Temp., salinity, DO, pH: 2/d; SS: 1/d; TSS: ≥1/wk; NH4-N, NO2-N, NO3-N, VSS, turbidity, RP: 1/wk; Alkalinity: 2/wk adjustments using NaHCO3 to maintain 160 mg/L as CaCO3
pH adjusted to >7 using Ca(OH)2 from day 33 on
= Nozzles
34 M
FAN
FAN
3 M
FF
2 hp
FF
= Water Flow2 hp
2 hp 2 hp
FF
100 m3 RWs – Greenhouse Water & Air Flow
ST
- Air Flow- Water Supply
Each RW has 14 a3 injectors One ST & one FF per RW Two 2 hp pumps per RW that can be operated independently or simultaneously,
depending on loading factors (e.g., biomass, DO concentration)
Drain = Pump Intake
Top View - 100 m3 RWs at Texas AgriLife
ST
ST
ST
Intake Filter PipePartition
Settling Tank
Belt FeederCatwalk Harvest Outlet
STFoam FractionatorFF
DO Probe
Har
vest
Bas
in
A Belt Feeder Netting
Valve
Freeboard
Catwalk
Nozzle Air Intake
Two 2 HP PumpsTwo 2 HP Pumps
YSI 5500D with Optical DO Probe
Materials & MethodsWater circulation, mixing & oxygenation in each
RW were maintained by 14 a3 injectors (a3 All Aqua Aeration, Orlando, FL) & two 2 hp pumps
Each RW had 2 YSI optical DO probes & 5500D inline monitoring system (YSI Inc., Yellow Springs, OH)
Commercial probiotic - ECOPRO (EcoMicrobials™, Miami, FL) - every second day to daily
No water exchange - FW added to maintain salinity
Foam Fractionator Operated with one a3 injector, flow rate ≈ 28
Lpm, fed from the pump’s side loop Use of fabric for dewatering and drying of
the organic particulate matterSettling Tanks Conical tank 2 m3, flow rate 20 Lpm, fed
from the pump’s side loop Use of fabric for dewatering and drying of
the organic particulate matter Targeted TSS of 200-300 mg L-1 & SS of
10-14 mL L-1
Shrimp were fed 40% CP feed with 9% lipid (Zeigler Bros., Gardners, PA)
Rations were initially determined using an assumed FCR of 1.2-1.3, growth of 1.5 g/wk, and mortality of 0.5%/wk, and were adjusted based on 2/wk growth samples & shrimp mortality
Feed was distributed continuously 24/7 using belt feeders
Materials & Methods
Vibrio in culture medium monitored 2/wk on TCBS and late in grow-out on RambaCHROM
Vibrio in hemolymph of moribund shrimp cultured on TCBS and RambaCHROM at harvest
Algal pigments in biofloc measured 1/wk
Materials & Methods Vibrio & Algae
Summary of water quality parameters* in two 100 m3
raceways over 38-d periodTemp. (oC)
Salinity (ppt)
DO(% Sat)
DO(mg L-1) pH
AM Mean 30.1 30.4 96.7 6.19 7.54Min 29.0 29.3 79.2 5.03 6.78Max 30.8 30.9 117.9 7.48 7.84
PM Mean 30.5 30.5 93.7 5.94 7.61Min 29.4 29.9 74.4 4.68 6.71Max 31.3 30.9 108.2 6.86 7.88
*No statistically significant differences between RWs - All WQ indicators were within the acceptable range for L. vannamei
0
100
200
300
400
500
600
700
1 6 11 16 21 26 31 36
TSS
(mg
L-1
)
Days
TSS B1 B2
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
4 9 14 19 24 29 34
NO
2-N
(mg
L-1
)
Days
NO2-N B1 B2
020406080
100120140160180200
4 9 14 19 24 29 34
NO
3-N
(mg
L-1
)
Days
NO3-N B1 B2
0
0.5
1
1.5
2
2.5
3
4 7 9 10 13 14 15 16 18 21 23 25 27 30 34 37
TAN
(mg
L-1
)
Days
TANB1 B2
y = 0.4573x - 24.477R² = 0.916; Pearson = 0.957 (P = 0.000)
-50
0
50
100
150
200
250
300
350
400
0 200 400 600 800 1000
Turb
idity
(NT
U)
TSS (mg L-1)
TSS / Turbidityy = 3.0922x + 93.438
R² = 0.2665; Pearson = 0.516 (P = 0.000)
0
50
100
150
200
250
300
350
400
0 20 40 60 80 100
Turb
idity
(NT
U)
SS (mL L-1)
SS / Turbidity
y = 0.0177x + 11.835R² = 0.0223; Pearson = 0.15 (P = 0.089)
0102030405060708090
100
0 200 400 600 800 1000
SS (m
L L
-1)
TSS (mg L-1)
TSS / SS
0
20
40
60
80
100
120
140
160
180
4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
Alk
alin
ity (m
g L
-1C
aCO
3)
Days
Alkalinity
B1 B2
Results Shrimp stocked in B1 experienced about 20%
mortality prior to stocking because of low DO, high water temperature, and high TSS levels when harvested juveniles were stocked in a small tank
A new wave of shrimp mortality started in B1 7 days after stocking quickly spreading to B2
Mortality rate increased over time forcing early termination of the study
0
50
100
150
200
250
1 4 7 10 13 16 19 22 25 28 31 34 37
Rec
over
ed d
ead
shrim
p da
y-1
Days
Daily Recovered Dead Shrimp
B1 B2
-
0.5
1.0
1.5
2.0
2.5
3.0
02468
101214161820
14 17 21 24 28 31 35 38G
row
th (g
/wk)
Av, W
t. (g
)
Days
Shrimp Growth Performance
Av. B1-B2 g/wk B1-B2
0
50
100
150
200
250
300
350
1 11 21 31 41 51 61 71 81 91 101 111 121
No.
mor
talit
ies r
ecov
ered
day
-1
Days
B1 B2Daily Recovered Dead Shrimp
ResultsGreen-colony forming Vibrio concentrations
increased in both RWs from Day 4 on reaching 14,300 CFU mL-1
The total Vibrio concentration increased as the trial progressed, particularly in the final week, reaching up to 27,750 CFU mL-1
0
5,000
10,000
15,000
20,000
3 8 11 15 18 22 25 29 32 36 39
CFU
mL-1
Days
B1 Yellow B1 GreenB2 Yellow B2 Green
0
10,000
20,000
30,000
40,000
3 15 25 36 46 57 67 95 116
CFU
mL-1
Days
Yellow Green Total
0%
20%
40%
60%
80%
3 15 25 36 46 57 67 95 116
Gre
en C
olon
ies B1 B2
Green Colonies
B1 by ColorColor by Raceway
Total Vibrio
Vibrio colonies in the 100 m3 culture medium
0
10,000
20,000
30,000
40,000
3 15 25 36 46 57 67 95 116
CFU
mL-1
B1 B2
Litopenaeus vannamei performance in a 38-day grow-out trial in two 100 m3 RWs
Raceway 1 Raceway 2Survival (%) 79.50 71.6Final weight (g) 18.37 19.01Growth Rate (g/wk) 2.20 2.31Yield (kg/m3) 6.02 6.92PER 1.25 1.59FCR 2.07 1.61
Conclusion The commercial probiotic may have suppressed Vibrio
concentrations but did not prevent mortalities entirely Stressors such as low DO, high temp. & TSS should be
avoided, especially during transfer, to reduce the risk of triggering pathogenic Vibrio outbreak
Monitoring Vibrio is a useful tool for predicting disease outbreaks
The study demonstrates the detrimental effect of pathogenic Vibrio on L. vannamei production in super-intensive, biofloc-rich water, and the need for more studies on prevention & control of Vibrio in these systems
The National Sea Grant, Texas A&M AgriLife Research for funding
Zeigler Bros. for the feed & funding YSI for the DO monitoring systemsKeeton Industries for the nitrifying bacteriaAquatic Eco-Systems for the foam fractionatorsColorite Plastics for the air diffusersFirestone Specialty Products for the EPDM linerFlorida Organic Aquaculture for funding a3 All-Aqua Aeration for providing the injectors
Acknowledgements
AQUATIC ECO-SYSTEMS